The applicant, Christopher A. DeSouza, Ph.D., is a physiologist currently holding a non-tenure track faculty appointment in the Department of Kinesiology at the University of Colorado. Dr. DeSouza has demonstrated a consistent focus and record of scholarly work in the area of physical activity, aging, and cardiovascular disease risk factors. His career goal is to develop an independent extramurally-funded research laboratory which has as its mission: 1) the study of physical activity as it pertains to human health, disease, and aging; and, 2) the scientific training of undergraduate and graduate students, and postdoctoral fellows. The Mentored Research Scientist Development Award for Minority Faculty would provide the Research and Career Development Plan. The research and career development plan consists of 2 primary elements: 1) the acquisition of an impressive number of new research skills; and 2) structured activities including formal course-work in research ethics and biostatistics; participation in journal clubs and seminar series; regular mentoring interactions; and attendance at scientific meetings. In addition to the sponsor, and advisory committee of established senior investigators and faculty members with expertise in all aspects of the proposed research and career development plan has been formed to mentor Dr. DeSouza. Research Plan. The general aim of the research project is to determine whether endothelial function declines with age in physically active populations and whether a program of regular aerobic exercise can restore some, if not all, of the loss in endothelial function in middle-aged and older sedentary adults. The general hypothesis is that endothelial function does not decline with age in physically active populations and that regular aerobic exercise can enhance endothelial function in middle-aged and older sedentary adults. Results supporting this hypothesis would provide new and useful physiological and clinical insight into the advocacy of regular aerobic exercise as a therapeutic strategy for both primary and secondary prevention of age-related endothelial dysfunction. Environment. The environment for Dr. DeSouza's training is outstanding. The sponsor, Douglas R. Seals, Ph.D., is an established investigator and mentor in integrative cardiovascular research, and has a well-funded laboratory. He and the host department will provide Dr. DeSouza all of the necessary resources to successfully complete his training. (End of Abstract)